EASILY GROWN ROCK PLANTS 107 
more conspicuous when the roots of the plant are well 
supplied with lime rubble, and in fact it is a good plan to 
firmly wedge mortar rubbish or limestone chippings among 
the roots of all Sempervivums. In regard to propagation 
nothing more is needed than to shake the soil from 
the roots of a clump, and pull the crowns asunder, planting 
or potting each rosette separately, pressing soil and bits 

SEMPERVIVUMS, SHOWING OFFSETS AND INFLORESCENCE, 
of porous stone or rubble tightly around the base. Even 
those rosettes that break away without roots will, if firmly 
fixed, develop new roots. It is a wise plan when planting 
Sempervivums to separate the plants and distribute them 
over a comparatively broad area, for thus they will spread 
until they form a united mass, whereas if a tightly packed 
cluster is planted, the tendency will be to force the central 
crowns far out of the soil, and in a season or two some of 
